Moszen - Moszen is a free web service that provides ambient sounds from natural environments to help you relax and avoid stress in your daily life.

Headspace - Meditation made simple. Brilliant things happen in calm minds.

Noizio - Feeling that the noise of the big city is too much for you to bear?

Timeless | Meditation - Personal practice meditation timer with guided instruction and multi-day courses.

Sleep Bug - Sleep Bug is the name of an ambient sound mixer that generates a wide range of scenes and music using the random sound effects.

Calm - Calm.com can help you reduce stress and increase calm.